FOXP1 and NDRG1 act differentially as downstream effectors of RAD9-mediated prostate cancer cell functions.

Metastatic progression is the key feature of prostate cancer primarily responsible for mortality caused by this disease. RAD9 is an oncogene for prostate cancer, and the encoded protein enhances metastasis-related phenotypes. RAD9 is a transcription factor with a limited set of regulated target genes, but the complete list of downstream genes critical for prostate carcinogenesis is unknown. We used microarray gene expression profiling and chromatin immunoprecipitation in parallel to identify genes transcriptionally controlled by RAD9 that contribute to this cancer. We found expression of 44 genes altered in human prostate cancer DU145 cells when RAD9 is knocked down by siRNA, and all of them bind RAD9 at their genomic location. FOXP1 and NDRG1 were down regulated when RAD9 expression was reduced, and we evaluated them further. We demonstrate that reduced RAD9, FOXP1 or NDGR1 expression decreases cell proliferation, rapid migration, anchorage-independent growth, anoikis resistance, and aerobic glycolysis. Ectopic expression of FOXP1 or NDRG1 partially restored aerobic glycolysis to prostate cancer cells with reduced RAD9 abundance, but only FOXP1 significantly complemented the other deficiencies. We thus show, for the first time, that RAD9 regulates FOXP1 and NDRG1 expression, and they function differently as downstream effectors for RAD9-mediated prostate cancer cell activities.

Clinically used antirheumatic agent auranofin is a proteasomal deubiquitinase inhibitor and inhibits tumor growth.

Proteasomes are attractive emerging targets for anti-cancer therapies. Auranofin (Aur), a gold-containing compound clinically used to treat rheumatic arthritis, was recently approved by US Food and Drug Administration for Phase II clinical trial to treat cancer but its anti-cancer mechanism is poorly understood. Here we report that (i) Aur shows proteasome-inhibitory effect that is comparable to that of bortezomib/Velcade (Vel); (ii) different from bortezomib, Aur inhibits proteasome-associated deubiquitinases (DUBs) UCHL5 and USP14 rather than the 20S proteasome; (iii) inhibition of the proteasome-associated DUBs is required for Aur-induced cytotoxicity; and (iv) Aur selectively inhibits tumor growth in vivo and induces cytotoxicity in cancer cells from acute myeloid leukemia patients. This study provides important novel insight into understanding the proteasome-inhibiting property of metal-containing compounds. Although several DUB inhibitors were reported, this study uncovers the first drug already used in clinic that can inhibit proteasome-associated DUBs with promising anti-tumor effects.

Effect of phospholipid composition on characterization of liposomes containing 9-nitrocamptothecin.

9-Nitrocamptothecin (9-NC), a newly developed camptothecin derivative, had poor solubility in any pharmaceutically acceptable solvents. One way of improving the solubility is to formulate the drug into liposomes. However, 9-NC has low affinity to lipid membranes resulting in a very low drug-to-liposome entrapment. We developed a novel liposome-based 9-NC formulation which was composed of soybean phosphatidylcholine (SPC), hydrogenated soybean phosphatidylcholine (HSPC), and cholesterol. Compared with conventional liposomes composed of only SPC and cholesterol, 9-NC/lipid molar ratio increased from 1:72 to 1:18 while incorporation efficiency was still maintained about 80%. In addition, after 9-NC was encapsulated into novel liposomes, pharmacokinetic results revealed an increase in area under the plasma concentration-time curve (AUC) and a decrease in distribution volume of 9-NC following intravenous administration to rats. Increased stability in plasma may account for the improved pharmacokinetic behavior of the novel liposomes. Effect of HSPC/SPC molar ratio on characterization of the novel liposomes was also investigated. Except for drug/lipid molar ratio and encapsulation efficiency, HSPC/SPC molar ratio had only a little effect on other properties of novel liposomes. In conclusion, the study suggests that the novel liposomes can act as promising carriers for hydrophobic substances such as 9-NC.

Effects of formulation factors on encapsulation efficiency and release behaviour in vitro of huperzine A-PLGA microspheres.

To develop a long-acting injectable huperzine A-PLGA microsphere for the chronic therapy of Alzheimer's disease, the microsphere was prepared by using o/w emulsion solvent extraction evaporation method based on a series of formulation design of the emulsion. The dialysis method was used for release analysis. The encapsulation efficiency and release amount of the microspheres were determined by UV/VIS spectrophotometry. The morphology of the microspheres was observed by scanning electron microscopy. The distribution of the drug within microspheres was observed by a confocal laser scanning microscope. The results indicated that the PLGA 15 000 microspheres possessed a smooth and round appearance with average particle size of 50 microm or so. The encapsulation percentages of microspheres prepared from PLGA 15 000, 20 000 and 30 000 were 62.75, 27.52 and 16.63%, respectively. The drug release percentage during the first day decreased from 22.52% of PLGA 30 000 microspheres to 3.97% of PLGA 15 000 microspheres, the complete release could be prolonged to 3 weeks. The initial burst release of microspheres with higher molecular weight PLGA could be explained by the inhomogeneous distribution of drug within microspheres. The encapsulation efficiency of the microspheres improved as the polymer concentration increase in oil phase and PVA concentration decreased in aqueous phase. The burst release could be controlled by reducing the polymer concentration. Evaporation temperature had a large effect on the drug release profiles. It had better be controlled under 30 degrees C. Within a certain range of particle size, encapsulation efficiency decreased and drug release rate increased with the reducing of the particle size.

Solubilization and pharmacokinetic behaviors of sodium cholate/lecithin-mixed micelles containing cyclosporine A.

The purpose of this study was to investigate the solubilization capacity of sodium cholate/lecithin-mixed micelles and to evaluate the potential of mixed micelles as a carrier of cyclosporine A for intravenous infusion. The mixed micelles were prepared by coprecipitation technique. The formulation components and preparation procedures, which may affect the solubilization of cyclosporine A, were studied. The dilution stability of cyclosporine A-containing mixed micelles was investigated. Pharmacokinetic behaviors of mixed micelles in rabbits after intravenous infusion were compared with Sandimmun. Results showed the strategies to increase the solubility of cyclosporine A include lowering the molar ratio of sodium cholate to lecithin, increasing the concentration of lecithin, and reducing the ionic strength of the dispersion medium and temperature. The largest solubility was found to be 5.42 +/- 0.16 mg/ml. The leakage of mixed micelles in 5% glucose (5.84%) was much less than that in saline solution (36.7%). The relative bioavailability of mixed micelles versus Sandimmun was 112 +/- 20%, and statistical analysis demonstrated both preparations were bioequivalent. Sodium cholate/lecithin-mixed micelles are promising carriers in the intravenous delivery of cyclosporine A, considering their capability of large-scale production and low-toxic property.

Effects of formulation factors on encapsulation efficiency and release behaviour in vitro of huperzine A-PLGA microspheres.

To develop a long-acting injectable huperzine A-PLGA microsphere for the chronic therapy of Alzheimer's disease, the microsphere was prepared by using an o/w emulsion solvent extraction evaporation method based on a series of formulation design of the emulsion. The dialysis method was used for release analysis. The encapsulation efficiency and release amount of the microspheres were determined by a UV/VIS spectrophotometer. The morphology of the microspheres was observed by scanning electron microscopy. The distribution of the drug within microspheres was observed by a confocal laser scanning microscope. The results indicated that the PLGA 15,000 microspheres possessed a smooth and round appearance with average particle size of 50 microm or so. The encapsulation percentages of microspheres prepared from PLGA 15,000, 20,000 and 30,000 were 62.75%, 27.52% and 16.63%, respectively. The drug release percentage during the first day decreased from 22.52% of PLGA 30,000 microspheres to 3.97% of PLGA 15,000 microspheres, the complete release could be prolonged to 3 weeks. The initial burst release of microspheres with higher molecular weight PLGA could be explained by the inhomogeneous distribution of drug within microspheres. The encapsulation efficiency of the microspheres improved as the polymer concentration increased in the oil phase and PVA concentration decreased in the aqueous phase. The burst release could be controlled by reducing the polymer concentration. Evaporation temperature had a large effect on the drug release profiles. It had better be controlled under 30 degrees C. Within a certain range of particle size, encapsulation efficiency decreased and drug release rate increased with the reducing of the particle size.

Transport of leuprolide across rat intestine, rabbit intestine and Caco-2 cell monolayer.

The purpose of this study was to investigate the transport mechanisms and causes of low bioavailability of leuprolide. The everted gut sac technique and Caco-2 cell monolayer were used to examine: (1) transport properties, enzyme degradation and apparent permeation coefficient (Papp); (2) the influence of trypsin inhibitor, EDTA, chitosan and alginate on drug transport; and (3) the effect of animal species on the intestinal transport. Results showed flux increased with increasing concentration of drug, showing a passive diffusion pathway. The enzyme degradation in rabbit gut was the highest. The Papp of (4.19 +/- 1.33) x 10(-5) cm/s in rat gut was the largest and the Papp of (5.20 +/- 0.20) x 10(-7) cm/s in Caco-2 cell the smallest. At a low concentration of drug, trypsin inhibitor had strong enhancement effect on the Papp by protecting enough drug for permeation. Chitosan had no effect on the activity of alpha-chymotrypsin. The increase in Papp was due to opening of the tight junctions and interaction with cells. In conclusion, both inhibition of proteolytic enzymes and opening the tight junctions to allow for paracellular transport improved the intestinal absorption. At low drug concentration, reduction of enzyme degradation is the most important factor.

Gastrointestinal absorption enhancement of insulin by administration of enteric microspheres and SNAC to rats.

The preparation and characteristics of insulin enteric microspheres (EMS) were studied and the gastrointestinal absorption enhancement of insulin by co-administering EMS with sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC) was determined. The w/o/w and o(1)/o(2) emulsion solvent evaporation methods were used to prepare insulin-hydroxypropyl methylcellulose phthalate (HPMCP) EMS. High-performance liquid chormatography determined the drug loading, entrapment efficiency, stability to pepsin, and drug dissolution rate in hydrochloric acid solution (pH 1.2) and phosphate buffer solution (pH 6.8). The hypoglycaemic effect was studied by orally administrating the insulin EMS and SNAC to rats. The particle size of EMS (o(1)/o(2)) and EMS (w/o/w) was about 500 and 30 micro m respectively, and drug loading was 7 and 3% respectively. After being incubated with 18 micro g/mL pepsin solution (pH 1) at 37 degrees C, only 20% of insulin in EMS (o(1)/o(2)) was digested within 4 h, while 60% of the insulin in EMS (w/o/w) was digested within 1 h. In hydrochloric acid solution (pH 1.2), EMS (o(1)/o(2)) had less drug dissolution than EMS (w/o/w). In phosphate buffer solution (pH 6.8), the entire drug release time of EMS (o(1)/o(2)) and EMS (w/o/w) was 75 and 10 min, respectively. After orally administering with SNAC, EMS (o(1)/o(2)) could decrease the blood glucose level of rats remarkably and maintain the hypoglycaemic effect for 4 h, while EMS (w/o/w) had just a weakly hypoglycaemic effect. The results showed that the characteristics-optimized EMS, i.e. EMS (o(1)/o(2)) incorporating SNAC, could enhance insulin absorption significantly in the gastrointestional tract by taking advantage of both protection from enzyme degradation and improvement of drug permeability.

Chitosan-coated liposomes: characterization and interaction with leuprolide.

The objective of the present work was to investigate the effect of chitosan concentration and lipid type on the characteristics of chitosan-coated liposomes and their interactions with leuprolide. Liposomes from lipid of high purity and low purity were prepared and coated by chitosan. Physical properties, drug entrapment efficiency, and stability upon dilution were respectively compared. Results showed that the particle size increment of liposomes from low purity lipid was larger than that from high purity lipid, indicating a thicker coating layer. The high zeta potential of particles from low purity lipid was thought to play an important role in the resistance to flocculation. As to particles from high purity lipid, polymer bridging caused flocculation at low polymer concentration while at high concentration, the adsorbed chitosan molecule led to steric stabilization. Drug entrapment efficiency decreased as chitosan was added to liposomes, showing the disturbance of bilayers. Upon dilution, the leakage of leuprolide from low purity liposomes was larger than that from high purity liposomes. In conclusion, low purity lipid possessed more negative charge and formed thicker adsorptive layer by stronger electrostatic attraction with chitosan. The interaction between chitosan and the polar head groups on the surface of phospholipid bilayers may interfere with leuprolide entrapped in liposomes and result in the leakage of leuprolide.

Optimal dosing of intravascular low-power red laser light as an adjunct to coronary stent implantation: insights from a porcine coronary stent model.

BACKGROUND: It is believed that restenosis following coronary interventions is the result of endothelial denudation that leads to thrombus formation, vascular remodeling, and smooth muscle cell proliferation. Low-power red laser light (LPRLL) irradiation enhances endothelial cell growth in vitro and in vivo, and reduces restenosis in animal models. The present study investigated the optimal dose of intravascular LPRLL therapy in the prevention of in-stent stenosis in a porcine coronary stent model. METHODS AND RESULTS: Selected right coronary artery segments were pretreated with a LPRLL balloon, delivering a dose of 0 mW during 1 min (group 1, n = 10), 50 mW during 1 min (group II, n = 10), or 100 mW during 1 min (group III, n = 10) before stenting. Quantitative coronary analysis of the stented vessel was performed before stenting, immediately after stenting, and at 6 weeks follow-up. The pigs were sacrificed, and histologic and morphometric analyses were conducted. At 6 weeks, minimal luminal stent diameter was significantly narrower in the control group compared to the 50-mW dose group (p < 0.05). These results were confirmed by morphometric analysis. Neointimal area was also significantly decreased in the 50-mW dose group. CONCLUSIONS: Intravascular LPRLL contributes to reduction of angiographic in-stent restenosis and neointimal hyperplasia in this animal model. The optimal dose using the LPRLL balloon system seems to be approximately 5 mW delivered during 1 min.

Pharmacokinetic behavior of cyclosporin A in rabbits by oral administration of lecithin vesicle and Sandimmun Neoral.

The present study was undertaken to investigate the incorporation of lipophilic polypeptide, cyclosporin A (CsA) into lecithin vesicular system and to compare its pharmacokinetics behavior with Sandimmun Neoral (CsA-NEO). Lecithin vesicles of cyclosporin A (CsA-VES) were prepared by the rotary evaporation method, treated further with sonication. Studies were carried out to characterize the vesicles on physical properties, content, entrapment efficiency, particle size, polydispersity and Zeta potential. Pharmacokinetic behaviors were studied in rabbits at dose of 30 mg/kg. Results showed CyA vesicles were spherical particles, with content of 3.137+/-0.060% mg/ml, entrapment efficiency of 98.91+/-0.80%, particle size of 63.89+/-4.75 nm, polydispersity of 43.2+/-6.1% and Zeta potential of -13 mV. The best model fitting experimental data was a two-compartment open model with first-order kinetics. The relative bioavailability of CsA-VES versus CsA-NEO was 105+/-21% (n=6) and statistical analysis demonstrated both preparations were bioequivalent. In conclusion, lecithin vesicles are promising carriers in the oral delivery of CsA, considering their absorption enhancement effect and low-toxic property.

[Permeation of buspirone hydrochloride across animal buccal mucosa and its mechanism].

AIM: To study the permeation of busprione hydrochloride across animal buccal mucosa and its permeation mechanism. METHODS: The in vitro penetration model was designed to investigate drug buccal mucosa permeability, and the influence factors (different animal oral mucosa, such as rabbit, guinea pig, pig, sheep and cow, drug concentrations and solution pH values) were measured. RESULTS: The permeability of rabbit buccal mucosa for busprione hydrochloride was the largest. The permeation rate was increased with solution pH and directly to the drug concentration. CONCLUSION: The transport way of busprione hydrochloride was passive diffusion and the transport channel was through cells.

[Transdermal delivery of cyclosporin A solubilized in mixed micelles through mice skin].

AIM: To investigate the transdermal delivery effects of cyclosporine A solubilized in mixed micelles composed of phospholipid and different surfactants. METHODS: When applied onto the excised abdominal skin of the mice occlusively, the enhancing effects of various mixed micelles on the penetration of cyclosporin A were assessed by an in vitro permeation technique. In vivo study was carried out by topical application of sodium cholate-phospholipid mixed micelles onto the mice skin and drug blood concentration was detected. RESULTS: In vitro, mixed micelles containing different surfactants displayed distinct permeability and corresponded to the following order: sodium cholate > sodium deoxycholate > Trition X-100 > Tween-20. In vivo, peak drug concentration was detected at 5 h and after that the concentration fell down slowly. CONCLUSION: Mixed micelles were shown to be efficient carrier for the transdermal delivery of the lipophilic polypeptide when kept in solution during the application process.

A novel platinum-iridium, potentially gamma radioactive stent: evaluation in a porcine model.

In-stent restenosis (ISR) is a major problem within stented arteries. Surface treatment of stents with platinum and gold were found to have the maximum charge with least neointima formation (NF). This study was designed to evaluate platinum (maximum electrical charge) as a material to make stents to reduce NF. Iridium was added to make an alloy suitable for stent manufacture, with the potential to make the stent radioactive. We implanted the novel platinum-iridium (PI) stent in 10 porcine coronaries and compared to the Palmaz-Schatz (PS) stent implanted in 8 coronary arteries. Six weeks after implantation, angiography of the stented vessel was performed before sacrifice. The coronaries were perfusion-fixed and stained, and vessel parameters were analyzed by computer-aided histomorphometry. The thrombus formation and the inflammatory response was less in the PI stent (0.04 +/- 0.1 vs. 0.24 +/- 0.2, P = 0.005; and 1.1 +/- 0.5 vs. 2.4 +/- 0.3, P < 0.001). The NF from PI-stented arteries was smaller in size than the PS controls (1.9 +/- 0.6 mm(2) vs. 2.4 +/- 0.4 mm(2), P = 0.06). However, PI stents presented with higher recoil than the PS stent (16% vs. 5%, P < 0.001). Platinum-iridium is a highly biocompatible material with high performance, low inflammatory response with small NF. This stent does not lead to thrombus formation and has the potential (due to the presence of iridium) to be irradiated to form a gamma radioactive stent. Cathet. Cardiovasc. Intervent. 51:364-368, 2000.

Enhanced transdermal delivery of tetracaine by electroporation.

The effect of electroporation on the transport of tetracaine through skin in vitro was studied using side-by-side compartment diffusion cells method. After achieving steady state by passive diffusion, fluxes of tetracaine achieved with passive diffusion, electroporative pulse and iontophoresis were compared. Electroporation (square-wave pulse, voltage 130 V, pulse time 0.4 s, pulse frequency 40 pulses min(-1)) or iontophoresis (0.2.mA cm(-2), lasting for 4 h) increased the transport of tetracaine through skin. The flux of tetracaine at 0.25 h after electroporation (pulse number 400) was 54.6+/-6.0 microg.cm(-2).h(-1), that after iontophoresis was 17.4+/-5.8 microg.cm(-2).h(-1) and that after passive diffusion was 8.2+/-0.5 microg.cm(-2).h(-1). In addition, the fluxes of tetracaine increased with the increasing of pulse number. From these results, it is clear that electroporation is effective in enhancing transdermal delivery of tetracaine and its function is better than iontophoresis.

Transdermal delivery of insulin in mice by using lecithin vesicles as a carrier.

The present study was undertaken to characterize the preparation of flexible lecithin vesicles containing insulin and to assess the enhancing effect of these flexible vesicles on the transdermal delivery of a hydrophilic protein. Both conventional and flexible vesicles were prepared by reverse-phase evaporation and treated further by sonication. The free drug was separated from vesicles by column chromatography and analyzed by HPLC. Both conventional and flexible vesicles were transparent colloidal dispersions. The particle size of the conventional and flexible vesicles was 73.5 nm and 87.1 nm with a polydispersity index of 44.5% and 15.6%, respectively. The entrapment efficiencies of conventional and flexible vesicles were 35% and 81%, respectively. When vesicles were nonocclusively applied onto the abdominal mice skin at a dose of 0.90 IU/cm2, in vivo hypoglycemic study showed the drop percentage of blood glucose by flexible vesicles was 21.42 +/- 10.19% at 1 hr, reached 61.48 +/- 8.97% at 5 hr, and was larger than 50% within 18 hr. Conventional vesicles, insulin solution, and saline had no hypoglycemic effect. Probably due to the incorporation or adsorption of a certain amount of insulin into the flexible vesicles during the mixing process, blank flexible vesicles mixed with insulin solution had a certain degree of hypoglycemic effect, though much less than the effect of flexible vesicles containing insulin (p < 0.05). Flexible vesicle may become a promising carrier for the transdermal delivery of hydrophilic polypeptides.

Microencapsulation and characterization of tramadol-resin complexes.

Tramadol was complexed with a sulfonic acid cation-exchange resin by a column method. Microencapsulation of tramadol-resin complexes (TRC) was carried out by the spray-drying method. The effect of ethylcellulose (EC) of various viscosities, different solvent systems and addition of plasticizers on microencapsulation were investigated. The morphology of microcapsules was characterized by scanning electron microscopy (SEM). Selected solvents having similar toxicity levels while various physico-chemical properties resulted in greatly different microcapsules. Regular particle morphology and sustained-release behavior were obtained when dichloromethane or ethyl acetate was used as the solvent system, whereas ethanol produced a substantial number of coalesced microcapsules and acetone produced apparently surface-smooth monomicrocapsules with faster release behavior. Three kinds of plasticizers affected the drug release rate similarly. On the addition of plasticizer (DEP), the drug release rate from the microcapsule obtained from low viscosity-grade EC reduced, while there was no alternation for those obtained from middle viscosity-grade EC. Compared to EC with a viscosity of 100 cP, which produced multi-microcapsules and released 60% of the drug within 1 h, microcapsules prepared with 10, 20 and 45 cP viscosity-grade EC showed slower drug release and regular and smooth morphology.

Lecithin vesicular carriers for transdermal delivery of cyclosporin A.

Two kinds of vesicles with and without the presence of sodium cholate (flexible vesicles and conventional vesicles) were prepared, using cyclosporin A as model drug. When applied onto the excised abdominal skin of mice non-occlusively, the enhancing effects of vesicles on the penetration of cyclosporin A were assessed by an in vitro permeation technique. The effect of sodium cholate micelles was also studied. In vivo study was carried out by topical application of vesicles onto the mice skin and drug serum concentration was detected. Results showed that after 8 h of administration, flexible vesicles transported 1.16 microg of cyclosporin A through per cm(2) mice skin and amounted to 1.88 microg 24 h later. The residual amount in the skin was 1.78+/-0.51 microg/cm(2). However, flexible vesicles failed to transport measurable amount of drug through pre-hydrated skin while deposited 2.39+/-0.26 microg/cm(2) into the skin. Conventional vesicles failed to transfer cyclosporin A into the receiver while accumulated 0. 72+/-0.19 microg/cm(2) of drug in the skin. Furthermore, 1 and 40% sodium cholate micelles precluded the transport of cyclosporin A. In vivo studies indicated that with the application of flexible vesicles, serum drug concentration of 53.43+/-9.24 ng/ml was detected 2 h later. After the stratum corneum of mouse skin has been destroyed by shaving, flexible vesicles transferred large amount of drug into blood, up to 187.32+/-53.21 ng/ml after 1 h of application. Conventional vesicles failed to deliver measurable amount of drug into the blood under normal skin condition. In conclusion, flexible vesicle is better than conventional vesicle as the carrier for transdermal delivery of cyclosporin A. Penetration and fusion have been suggested to be two major functional mechanisms. Hydration is detrimental to the enhancement effect. Stratum corneum constitutes main barrier to the transport of lipophilic cyclosporin A.

[Transdermal delivery mechanisms of lecithin nanoparticles with cyclosporin A through mice skin].

AIM: To investigate the transdermal delivery mechanisms of the flexible nano-liposomes, conventional nano-liposomes and lecithin-cholate mixed micelles through mouse skin. METHODS: Liposomes and micelles were applied onto the mouse skin non-occlusively in vitro and in vivo, then the drug concentrations in the skin, receiver and blood were determined. RESULTS: In vitro permeation studies showed that flexible nano-liposomes and mixed micelles transported measurable amount of cyclosporin A through the skin. Conventional liposomes precluded drugs permeate through the skin while deposited it in the skin. In vivo studies indicated that blood concentration reached peak value at 8 h after the application of flexible nano-liposomes. Both conventional nano-liposomes and mixed micelles failed to deliver measurable amount of drug into the blood. CONCLUSION: Liposomes fuse with the skin. Flexible nano-liposomes penetrate through the skin under the pressure of hydration force. Mixed micelles promote transfer in state of solution.

Intravascular low-power red laser light as an adjunct to coronary stent implantation: initial clinical experience.

Low-power red laser light (LPRLL) irradiation enhances endothelial cell growth in vitro and in vivo and reduces restenosis in animal models. The present study reports the preliminary clinical experience in our center. Eighty-one patients were treated with LPRLL, 30 mW/1 min, for in-stent restenosis (n = 27), elective stenting for recurrent restenosis (n = 16), and stenting for treatment of a suboptimal PTCA result (n = 38). All interventions were successful and no major adverse events due to LPRLL therapy were observed. At follow-up, 12 patients (14.8%) underwent an early control coronarogram due to target vessel restenosis. At 6 months, another 20 patients showed a significant restenosis of the target vessel. Preliminary clinical evaluation demonstrates that LPRLL is feasible and safe. The preliminary results suggest that LPRLL results in a decrease of in-stent restenosis when used during primary stenting.